Let's break this down. We're going to add 1664 and 8113 together.

Step 1: We'll start by adding the digits 4 & 3 in column 1 and get 7.

Step 2: We'll start by adding the digits 6 & 1 in column 2 and get 7.

Step 3: We'll start by adding the digits 6 & 1 in column 3 and get 7.

Step 4: We'll start by adding the digits 1 & 8 in column 4 and get 9.

So, 1664 + 8113 = 9777.

